             pop (-> tribe .population total-persons)
             world (.world game)
             pos (.position tribe)
-            possible-destinations (filter #(pos-free? game %) (land-cells-around world pos 3))]
+            possible-destinations (filter #(pos-free? game %) (land-cells-around world pos migration-radius))]
         (if
           (and (> pop 35) (< c 0.9) (not (empty? possible-destinations)))
           (/ (opposite c) 2.7)

    (fn [game group]
      (let [ world (.world game)
             pos (.position group)
             possible-destinations (filter #(pos-free? game %) (land-cells-around world pos 3))]
        (if (empty? possible-destinations)
          0.0
          (let [p (prosperity-in-pos game group pos)

      (let [ world (.world game)
             pos (.position tribe)
             sp (split-pop (.population tribe))
             possible-destinations (filter #(pos-free? game %) (land-cells-around world pos migration-radius))
             preferences (map (fn [pos] {
                                          :preference (perturbate-low (prosperity-in-pos game tribe pos))
                                          :pos pos
